The present invention relates to a device for processing sound or other sonic information with applicability in situations where there is difficulty perceiving that sound or information, for example, at times when it is difficult to understand speech. The device is self-contained and fits on the user's head similar to a headset.
There are many situations where an individual may wish to better perceive sound or other sonic information in his or her environment. A common situation which may occur is difficulty in understanding speech, due to, for example, interfering noise or limited hearing capabilities. Another situation in which there may be difficulty perceiving sonic information is during the evaluation of a vehicle design or while maintaining mechanical equipment. In these situations, a listener may wish to perceive sounds in a limited frequency range in order to diagnose problems or to more easily locate the source of a sound. Other applications may include elimination of noise during the operation of radio or telephony equipment, elimination of interfering sounds such as clicks and buzz while listening to speech or music, and the processing of either infrasonic or ultrasonic sound such that it can be heard within the frequency range of human hearing.
Of particular interest are situations in which there is difficulty in understanding speech. Generally, difficulty in understanding speech is due to the inability of a person to sense weak sounds or the person's inability to hear clearly in the presence of interfering noise. Many different signal processing schemes have been employed to assist in listening to speech. For example, U.S. Pat. No. 5,553,151 to Goldberg and U.S. Pat. No. 5,131,046 to Killion, et. al. are analog circuits for processing sound for assisting the hard of hearing. Digital sound processing technology is described, for example, in U.S. Pat. No. 6,937,738 to Armstrong, et al and U.S. Pat. No. 6,292,571 to Sjursen.
Hearing aids and other assistive listening devices are designed to ameliorate hearing loss. Present-day hearing aids are generally small devices which fit into the ear of the user. Some hearing aids are so small that they fit entirely in the ear canal and can barely be seen, and others are larger and comprise a case which rests behind the ear of the user and a custom-fitted earmold which fits into the user's ear canal.
Difficulties which are evident to users of modern hearing aids include discomfort because the aid may fit tightly in the ear in order to prevent feedback. Further, the ear canals of hearing aid users may change shape over time, requiring refitting. Another difficulty with modern hearing aids is the complexity of the fitting process itself. A hard of hearing person must first be tested to determine his or her hearing loss characteristics and also generally undergo an ear canal impression, necessary for determination of the outer shape of either the hearing aid itself or an earmold. The hearing aid then must be delivered to the user, which often involves mechanical modification of the portion which fits into the ear, as well as adjustment of the hearing aid's characteristics. The process is generally time-consuming and expensive.